JKBMS B2A20S20P w/Screen Connecting RS485 ?

[MattMan119]

Anyone had any luck connecting RS485 to the JKBMS B2A20S20P w/4.2 LCD

The screen works perfectly, but i can not get the rs485 to work .. anyone had any luck with this kind of BMS?

Got the connector

This to JKBMS Port

Amazon.com

This to USB

https://a.co/d/5IQCELW

This is BMS ->

 

[timselectric]

Wrong converter.

This one worked great for my system.

Amazon.com

 

[MattMan119]

Wrong converter.

This one worked great for my system.

Amazon.com

I will give it a try .. Tried everything I can think of, figured it has to be something stupid .. Thanks!

 

[timselectric]

I will give it a try .. Tried everything I can think of, figured it has to be something stupid .. Thanks!

I had the wrong one for the first try, also.
I didn't realize that there were different types.

 

[MattMan119]

I had the wrong one for the first try, also.
I didn't realize that there were different types.

Damn I hope you’re are right,. It will be here tomorrow and I will have it setup by the end of the day .. i been using the BT Monitor.. but that has to be close to the BT device so it is located in the compartment instead of inside .. and with summer coming I want to get it inside..

 

[timselectric]

Mine are working great.
Connected to Solar Assistant.

 

[MattMan119]

Mine are working great.
Connected to Solar Assistant.

It gets data in app and SA .. app shows nothing, and SA shows invalid data received … Ugg this look right?

 

[timselectric]

Looks right.
Double check the connections. They are tiny wires.

 

[timselectric]

Power led should be on steady.
TXD and RXD should be blinking as data is transferred.

 

[MattMan119]

Power led should be on steady.
TXD and RXD should be blinking as data is transferred.

Yep they blink and debug shows it responding but it does not show data or work for SA .. hmmm guess I could download specs and see if what it’s sending is real data

 

[timselectric]

And you have the setup correctly in Solar Assistant?

 

[MattMan119]

And you have the setup correctly in Solar Assistant?


View attachment 286511

This is the option .. looks right .. the other is the eg4 connector..

And the JKBMS app does not show status .. but does get this data in the debug .. so it is answering .. just something wrong with format i guess.. This looks like three different packs of data.. Not sure what is wrong but it is across the board.. Can you check the wire colors for me? Yellow is A

[20:01:33,705] FF EC C0 98 07 FF 8E FE 8E FE 8E FF 8E FF 8E FF 87 FD 8E FF 8E FF 8E FF 87 FF 8E FF 8F FF 8E FC 8E FD 8E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF 80
[20:01:33,706] 00 FF 8E 10 20 A0 40 5E 00 7F 40 7E 40 6E 00 5F 00 7F 40 BC 00 03 C2 01 EE 03 CC 01 FC 01 C0 01 C2 01 E0 01 FC 01 02 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 40
[20:01:33,717] 40 80 80 00 FF 0F 08 68 90 81 00 FF FB 1A FC 1E 04 00 08 00 10 00 FA FC 6E 41 00 C0 3A 10 00 22 00 40 00 87 FF 0F 88 1F 10 00 20 4F 3F 07 14 30 08 00 10 00 20 00 40 00 80 00 00 00 00
[20:01:33,720] 00 FF 80 40 40 80 80 C6 10 20 20 22 00 40 FC 01 03 02 02 04 44 9E 04 04 08 28 10 50 20 A0 08 00 90 B4 0C 0B 00 00 00 00 20 40 40 80 80 00 F7 C0 9C 18 FD 21 27 00 40 00 C0 FC 00
[20:01:33,724] 00 00 00 00 00 00 00 00 00 00 01 FE FE 34
[20:01:33,735] 00 08 F8 10 20 20 C0 7E 10 22 06 02 18 44 F8 FF

[20:01:34,497] FF C8 83
[20:01:34,504] 90 86 FD 8E FC 8E FF 86 FF 8E FC 8E FF 47 7F 88 8E FF 8E FE 8E FF 8E FF 8E FE 8E FF 8E FE 8E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF 80
[20:01:34,510] 00 FF 8E 00 90 C0 A0 6F 40 5E 40 5E 40 6E 00 5F 40 FF 80 38 00 78 00 78 00 7B 00 BD 00 BF 00 78 00 78 00 7C 00 7F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 3F 40
[20:01:34,519] 00 80 00 00 FC 0F 00 28 24 81 00 3C FF 1E F8 1E 00 00 00 00 FF 3E 10 00 F0 3A 10 00 04 08 08 F0 C8 0F 80 1F 10 00 DF F4 1C 40 C0 20 00
[20:01:34,522] 00 00 00 00 00 00 00 00 00 00 FF 00 00 CE 10 20 A0 44 40 88 FC 01 03 02 00 00 C4 9A 00 00 01 00 01 02 0F 00 00 3E 89 BC 02 00 00 00 3F 01 00 00 00 00 FF 10 31 38 FC 21 66 00 80 FE 00 40 00 80 00 00 00 00 00
[20:01:34,528] 00 00 00 00 03 FE FE 14 08 08 F8 10 20 20 00 FF 00 E8 06
[20:01:34,540] 02 18 44 F0 FF

[20:01:35,308] FF C8 03
[20:01:35,313] 07 FE 86 FF 8E 8E FF 47 FE 47 FE 8E FE 47 FE 8E FE 8E FE 86 FF 8E FF 8E FF 8E FC 8E FF 8E FE 8E 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF 80
[20:01:35,320] 00 FF 8E 10 90 E0 80 7F 00 7E 40 6E 40 4E 40 BF 80 FE 00 78 00 78 00 78 00 79 00 79 00 7F 00 03 C2 03 E0 01 FE 03 02 02 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 01 00 00 00 00 FC 0F
[20:01:35,325] 00 E8 7F 20 20 CF FF 1A F8 1E 04 00 08 00 10 00 20 00 3F FE 6E 01 40 C0 3A 10 00 22 00 40 80 84 FE 0F 88 1F 00 00 50 E4 1C 40 E0 20 40 40 80 80 00 00 00 00 00 00 00 FF 80 40 40 80 80 C6 00 20 80 44 00
[20:01:35,331] 14 01 01 02 02 00 C4 9A 00 00 00 01 00 03 02 0F 00 00 3E 62 5E 81 80 00 00 00 20 01 00 00 F7 50 31 38 FC 21 46 40 00 00 FC 00 40 00 80 00 00 00 00 00 00 00 00 01 FE FE 14 00 08 F8 10 00 00 F8 00
[20:01:35,349] 44 06 02 18 40 F0 FF

 

[Shawn Hayes]

…following along to see if this works

 

[timselectric]

This is the option .. looks right

Yes

Can you check the wire colors for me?

Colors are the same as mine.

 

[MattMan119]

Yeah I switched them and got no data .. the data is just wrong coming back from BMS .. wonder what brand it is.. make a fake BMS? May look around and see if I can find out what rs485 it is.. cause the JKBMS software don’t like it ..and SA don’t like it, but it IS responding to inquiries…

 

[MattMan119]

Looks like a real BMS.

 

[timselectric]

Weird

 

[MattMan119]

Looks like this has been a subject prior to now .. (and this is my version : hardware version V11A, software version V11.54. )

P

Thread 'JK BMS B2A8S20P (and family members)'

Nov 30, 2024

The JK_BMS company : their hardware engineers are doing a great job. Their software engineers are too low level. JK top-management doesn't care ....
I'm checking the JK BMS protocols at the lowest possible level : with the logic analyzer. (((( no confidence in all those higher level hocus-pocus software stuff .... ))).
By now I have a large collection of examples about the JK BMS software "skills".

The popular B2A8S20P has a CAN port. On hardware version V11.XW , software version V11.287H : modify the device address (via the bluetooth app) will result in a modified CAN ID . Device...

• Pepijntje Madurodam
• Replies: 10
• Forum: BMS (Battery Managment Systems)

• 

 

[MattMan119]

I tested today, on updating the device number within the app.. and it only responds to the correct device numbers.. So it has to be the older version of the RS485?

I am selecting from a very limited list in the options in UART Protocol "001 -JK BMS RS485 Modbus V1.0"

Is this the same thing you have selected?

 

[timselectric]

Is this the same thing you have selected?

I didn't select the protocols on the BMS's.
I just selected "USB JK RS485" in Solar Assistant.

 

[MattMan119]

I didn't select the protocols on the BMS's.
I just selected "USB JK RS485" in Solar Assistant.

Can you see what one was already selected? I assume it is the same, cause I don't think i changed mine .. but figured i better check everything at this point.

 

[timselectric]

Can you see what one was already selected? I assume it is the same, cause I don't think i changed mine .. but figured i better check everything at this point.

You will have to tell me where to look. I'm not seeing it, anywhere in the BMS app.

 

[MattMan119]

Hey thanks … the second tab on the app … the UART is the one I need .. click on it and I want to see the options , and the one selected..

 

[timselectric]

I don't have any of that.

 

[MattMan119]

I don't have any of that.


View attachment 286778

Oh you have one of the new ones.. What is the hardware and software version on the about page.. (you can see that in the three dots at the top right) ..

I assume this is an old BMS .. i bet your a V14 or V15